1. Field of the Invention
The present invention relates to a synergistic insecticidal composition containing a Chloronicotynyle compound and an Organophosphorus compound and a process thereof for making the composition.
2. Description of Related Art
Enhancement of agricultural produce requires the protection of the crops and its produce from pest damage. Various chemicals and their formulations have been developed and are in use currently for the effective management of insects and pests. Due to non-judicious use of the hitherto known pesticides, the pests have built up a resistance to many pesticides and it has becomes hard to kill them. Physically compatible pesticide mixtures exhibit better pest management. These mixtures show multifaceted advantages than when applied individually, showing a synergistic effect.
The need for more food has to be met through higher yields per unit of land, water, energy and time. Excessive use of mineral fertilizers and chemical pesticides has caused soil degradation, ground water pollution and the spread of the pest's resistant to pesticides in several areas. Hence their judicious use includes avoiding prophylactic sprays, adopting strip treatment, spot application to only those areas with heavy incidence of pests, application to the soil to avoid direct contact with the natural enemies and using selective or non-persistent pesticides. The systemic pesticides are sprayed at a concentration of 0.02 to 0.05 percent active ingredient. The contact pesticides are sprayed at 0.05 to 0.07 or even 0.1 percent active ingredient. The soil application of the granular systemic insecticides varies from 1 to 2 kg a.i./ha. The fungicides are applied up to 2 g/l depending upon the chemical used, pest species and season of the application.
Processes for insecticidal agents and compositions have been developed to control insect pests and in practice have been used as a single or a mixed agent. However, processes for economically efficient and ecologically safe insect control compositions are still being sought. A process for the preparation of insecticidal compositions which allows for reduced effective dosage rates, increased environmental safety and lower incidence of insect resistance are highly desirable. Although the rotational application of insect control agents having different modes of action may be adopted for good pest management practice, this approach does not necessarily give satisfactory insect control. Further, even though combinations of insect control agents have been studied, a high synergistic action has not always been found. Obtaining an insecticidal composition which demonstrates no cross-resistance to existing insecticidal agents, no toxicity problems and little negative impact on the environment is extremely difficult.
Prior U.S. patent applications describe the insecticidal mixtures of Chloronicotynyle compounds with one or more synergistic compound(s) selected from certain specific insecticide compounds. Amongst these synergistic compounds only three compounds belonging to the organophosphorus compounds, namely O,O-dimethyl S-(4-oxo-1,2,3-benzotriazine-3-methyl) dithiophosphate (trade name M-Gusathion); O-ethyl O-(4-bromo-2-chlorophenyl)-s-N-propyl thiophosphate (trade name Curacron); O,S-dimethyl phosphoamidothioate (trade name Tamaron) have been specified to impart synergism. No other compounds falling under this group have been stated. This means that the other compounds falling within the group of organophosphorus compounds have not been demonstrated to provide a synergistic effect when combined with Chloronicotynyle compounds according to the inventions disclosed in prior US patent applications.
Compounds other than organophosphorus compounds which can be combined with Chloronicotynyle compounds consist of 3,5-dimethyl-4-methylthiophenyl N-methylcarbamate [Mesurol]; 4-bromo-2-(4-chlorophenyl)-2-(ethoxymethyl)-5-(trifluoromethyl)-1H-pyrrol-e-3-carbonitrile [AC 303, 630]; N-[2,6-bis(−1-methylethyl)-4-phenoxyphenyl)-N′-(1,1-dimethylethyl)-thiourea [CGA 106 630; Polo]; abamectin; ethyl 3-t-butyl-1-dimethylcar-bamoyl-1H-1,2,4-triazol-5-ylthio)-acetate [Triazuron]; 6,7,8,9,10,10-hexachloro-1,5,5A,6,9,9A-hexahydro-6,9-methane-2,4,3-benzodioxathiepine 3-oxide [Endosulfan; Thiodan]; trans-5-(4-chlorophenyl)-N-cyc-lohexyl-4-methyl-2-oxo-3-thiazolidine-carboxamide [Cesar; Hexythiazox]; 3,6-bis-(2-chlorophenyl)-1,2,4,5-tetrazine [Clofentezin; Apollo]; ethyl [2-(4-phenoxyphenoxy)-ethyl]carbamate [Fenoxycarb; Insegar]; 2-[1-methyl-2-(4-phenoxyphenoxy) ethoxy]pyridine [Pyriproxyfen; Tiger]; N-cyclopropyl-1,3,5-triazine-2,4,6-triamine [Cyromazine]; benzoic acid [-2-benzoyl-1-(1,1-dimethyl)]hydrazide [RH 5849]; 5-amino-3-cyano-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-trifluoromethylthionopyrazole [Fipronil]; cis-(2,3,5,6-tetrafluoro-4-methylphenyl)methyl-3-(2-chloro-3,-3,3-trifluoro-1-propenyl)-2,2-dimethyl-cyclopropane-carboxylate [Tefluthrin; Force]; 1,5-bis-(2,4-dimethylphenyl)-3-methyl-1,3,5-triazape-nta-1,4-dione [Amitraz]; 3,5-dimethylbenzoic acid 1-(1,1-dimethylethyl)-2-(4-ethylbenzoyl)hydrazide [RH 5992]; N-[[2,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy) phenyl]-aminocarbonyl]-2,6-difluorobenzamide [Match]; (4-ethoxyphenyl)-[3-(4-fluoro-3-phenoxyphenyl) propyl] dimethylsilane [HOE 498]; and (E)-4,5-dihydro-6-methyl-4-[(3-pyridinylmethylene)amino]-1,2,4-triazin-3-(2H)-one [Chess].
Most of the above mentioned compounds employed in the composition resulting in synergism are all earlier generation insecticides having high toxicity. Many of these compounds are currently restricted and/or banned for use in certain countries due to their toxicity. Therefore, though the compositions disclosed above have synergistic activity, their practical application for use is either limited or banned
The invention disclosed in prior US applications does not disclose the use of any other advanced and safer organophosphorus insecticide such as Acephate, Phosphamidon, Chlorpyrifos Azarnethiphos, Azinphos-ethyl, Azinphos-methyl, Cadusafos, Chlorethoxyfos, Chlorfenvinphos, Chlormephos, Chlorpyrifos, Chlorpyrifos-methyl, Cumaphos, Cyanophos, Demeton-5-methyl, Diazinon, Dichlorvos, Dicrotophos, Dimethoate, Dimethylvinphos, Dioxabenzofos, Disulfoton, Ethion, Ethoprophos, Famphur, Fenitrothion, Fenthion, Fonofos, Formothion Heptenophos, Isazofos, Isofenphos, Isoxathion, Malathion, Mecarbam, Mephosfolan, Methidathion, Mevinphos, Monocrotophos, Naled, Omethoate, Oxydemeton-methyl, Parathion, Parathion-methyl, Phenthoate, Phorate, Phosalone, Phosmet, Phosphamidon, Phoxim, Primiphos-ethyl, Primiphos-methyl, Profenofos, Propaphos, Propetamphos, Prothiofos, Pyraclofos, Quinalphos, Sulfotep, Sulrpofos, Temephos, Terbufos, Tetrachlorvinphos, Thiometon, Triazophos, Vamidothion. This means that there does not appear to be any known advanced and safer organophosphorus compounds having synergistic effect when combined with Chloronicotynyle compounds.
In addition, the invention disclosed in the prior US applications describes only the effect of using two insecticidal compounds as an admixture in a tank-mix form at the time of the application on crops. In other words the ingredients have to be mixed as and when required at the place of application. In short, the inventions disclosed in the prior patent applications do not result in a compatible and storage stable formulation product, prepared in the manufacturing plant and made available to use in a packed container on a shelf. It also does not disclose the specific concentrations or concentration range of the compound that exhibits synergistic effects. This means that if the ingredients are mixed in advance and kept, their activity may either be reduced or totally lost. Thus, the composition cannot be prepared as a ready-to-use composition.
Thus, there is need to develop and improve insecticidal composition for a variety of reasons including: 1) to increase agricultural yield; 2) to provide a composition having high synergistic action; 3) to provide a composition having no cross resistance to existing insecticidal agents; 4) to avoid excess loading of the toxicant to the environment; and 5) to negligibly impact environmental safety. A need also exists for synergistic insecticidal compositions which could be physico-compatible formulations in the form of storage stable, safely packed, ready-to-use formulation.